JP2007065550A - Illuminator and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illuminator which is made compact as a whole, and also, which can obtain bright illuminating light, and to provide a projector. <P>SOLUTION: The illuminator includes a plurality of light source apparatuses 10A and 10B for emitting light, and a plurality of collimating optical systems 11A, 12A, 11B and 12B separately including a plurality of lenses for collimating the exit light beams emitted from the plurality of light source apparatuses 10A and 10B, and among the plurality of collimating optical systems 11A, 12A, 11B and 12B, at least one of the collimating optical systems 11A, 12A, 11B and 12B is arranged so that the optical path between the plurality of lenses may cross the other optical path. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lighting device and a projector.

  In recent years, it has been proposed to use, for example, a solid light emitting element as a light source device as a light source of a projector. In particular, a light-emitting diode (hereinafter referred to as “LED”) that is a solid-state light-emitting element is characterized by being ultra-compact, ultra-light, and long-life. Further, LEDs have been improved in brightness and efficiency by development and improvement for use for illumination purposes. For this reason, in order to reduce the size and power consumption of the projector, it is expected that an LED will be used for the illumination device of the projector, and an illumination device using the LED as a light source is used to illuminate a light modulation device such as a liquid crystal light valve. An image display device has been proposed (see, for example, Patent Document 1).

In the image display device described in Patent Document 1, a plurality of light source devices are arranged in parallel, the light emitted from these light source devices is converted into parallel light by a convex lens, and then the amount of illumination light is emitted by a multi-lens array. The distribution is uniform.
JP 2000-131762 A

  However, in the image display device described in Patent Document 1, if a plurality of light source devices are used in order to obtain brighter illumination light, a plurality of light source devices must be arranged in parallel. It will increase in size.

  SUMMARY An advantage of some aspects of the invention is that it provides an illumination device and a projector that are small in size and capable of obtaining bright illumination light.

In order to achieve the above object, the present invention provides the following means.
An illuminating device of the present invention includes a plurality of light source devices that emit light, and a plurality of collimating optical systems each of which includes a plurality of lenses, each of which collimates the light emitted from the plurality of light source devices. And at least one of the plurality of collimating optical systems is arranged such that an optical path between the plurality of lenses intersects with another optical path.

  In the illumination device according to the present invention, the light emitted from the plurality of light source devices is collimated by the collimating optical system. At this time, at least one collimating optical system among the plurality of collimating optical systems is arranged such that the optical path between the plurality of lenses intersects with another optical path. Thus, by crossing with other optical paths, the space between the plurality of lenses used in the collimating optical system can be reduced as compared with the case where the light source devices are arranged in parallel and the parallel light is emitted as in the conventional case. It can be used effectively. Therefore, even if a plurality of light source devices are used, the entire device can be reduced in size and bright illumination light can be obtained.

In the illumination device of the present invention, it is preferable that the collimating optical system is a telecentric optical system.
In the illumination device according to the present invention, since the collimating optical system is a telecentric optical system, the angle of the principal ray of parallel light converged on a predetermined region of the irradiation surface can be reduced, so that the illumination efficiency is improved. be able to. Moreover, a space is formed between a plurality of lenses by using a telecentric optical system. Therefore, it is possible to reduce the size of the entire device by intersecting the emitted light emitted from the light source device in this space.

  In addition, the illumination device of the present invention includes a plurality of light guide elements that uniformize the illuminance distribution of the emitted light emitted from the plurality of collimating optical systems, and at least one of the plurality of light guide elements is The optical axis is preferably arranged so as to intersect the optical axis of the emitted light emitted from the collimating optical system.

  In the illuminating device according to the present invention, by arranging the optical axis of the emitted light emitted from the collimating optical system and the optical axis of the light guide element so as to intersect with each other, without providing a separate space for the light guide element, It is possible to make the illuminance distribution of the emitted light emitted from the light source device uniform. Therefore, even if a plurality of light source devices are used, the entire device can be reduced in size, and bright and uniform illumination light can be obtained.

  A projector according to the present invention includes the above-described illumination device, a light modulation device that modulates light emitted from the illumination device in accordance with an image signal, and a projection device that projects light modulated by the light modulation device. It is characterized by that.

  In the projector according to the present invention, the light emitted from the illumination device enters the light modulation device. Then, the image modulated by the light modulation device is projected by the projection device. At this time, since the illumination device is small and bright illumination light as described above, a projector using the illumination device can project a clearer image.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size. In the following description, an XYZ orthogonal coordinate system is set as necessary, and the positional relationship of each member will be described with reference to this XYZ orthogonal coordinate system.

[First Embodiment]
A lighting device according to a first embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 1, the illumination device 1 includes a first LED (light source device) 10A that emits light in the + X-axis direction, a second LED (light source device) 10B that emits light in the + Y-axis direction, The first and second collimator lenses (collimating optical systems) 11A and 11B that collimate the emitted light emitted from the 2LEDs 10A and 10B and the emitted light emitted from the first and second collimator lenses 11A and 11B are condensed. First and second condensing lenses (parallelizing optical systems) 12A and 12B, and first and second rod integrators for uniformizing the illuminance distribution of the light collected by the first and second condensing lenses 12A and 12B (Light guide elements) 13A and 13B. The collimating optical system of the present embodiment is composed of a first collimator lens 11A, a first condenser lens 12A, a second collimator lens 11B, and a second condenser lens 12B.

The first rod integrator 13A has a reflecting surface 13a that is emitted from the first condenser lens 12A and reflects light in the + X-axis direction in the + Y-axis direction, and guides the incident light in the + Y-axis direction. It is like that. In addition, the second rod integrator 13B reflects the light guided from the second condenser lens 12B and reflected in the + X-axis direction in the + Y-axis direction and the light guided in the + Y-axis direction in the + Y-axis direction. And a reflective surface 13c. These reflection surfaces 13a, 3b, and 13c are inclined by approximately 45 degrees with respect to the Y axis, and a reflection film that reflects incident light is formed on these reflection surfaces 13a, 13b, and 13c. The reflective film is formed, for example, by coating a dielectric multilayer film. Further, the light emitted from the first and second rod integrators 13 </ b> A and 13 </ b> B is made uniform by the rod integrator 15.
Further, the first and second rod integrators 13A and 13B and the rod integrator 15 are rectangular column-shaped structures made of a light-transmitting material such as glass or transparent resin.

The optical system including the first and second collimator lenses 11A and 11B and the first and second condenser lenses 12A and 12B is a telecentric optical system as shown in FIG.
FIG. 2 is a schematic diagram showing the configuration of the telecentric optical system 20 of the present embodiment. The telecentric optical system 20 forms an image on each of the first and second rod integrators 13A and 13B. The distance between the first and second collimator lenses 11A and 11B and the first and second condenser lenses 12A and 12B is f1 (focal length of the collimator lens) + f2 (focal length of the condenser lens). . The first and second collimator lenses 11A and 11B and the first and second condenser lenses 12A and 12B have both-side telecentricity. However, the lens shape, size, arrangement interval and number, telecentricity, magnification and other lens characteristics can be appropriately changed according to required characteristics, and are not limited to the example of FIG. Further, although the first and second collimator lenses 11A and 11B and the first and second condenser lenses 12A and 12B have been described using only one lens, they may be configured to include a plurality of convex lenses and concave lenses. good.

  Further, as shown in FIG. 1, the emission surface of the first LED 10A faces the + X-axis direction, and the second LED 10B is arranged facing the + Y-axis direction. The emitted light emitted from the first collimator lens 11A and the emitted light emitted from the second collimator lens 11B are orthogonal (intersect). In other words, the first and second collimator lenses 11A and 11B and the first and second condenser lenses 12A and 12B are configured to generate parallel light emitted from the first collimator lens 11A and parallel light emitted from the second collimator lens 11B. The first and second condenser lenses 12A and 12B, which are the next optical systems, are arranged so as to be orthogonal to each other. That is, the optical path of the collimating optical system consisting of the first collimator lens 11A and the first condenser lens 12A is the optical path of the collimating optical system consisting of the second collimator lens 11B and the first condenser lens 12B (other optical paths). ) And are arranged to intersect.

Next, the illumination method of the illuminating device 1 which concerns on this embodiment comprised in this way is demonstrated below.
First, the emitted light emitted from the first LED 10A is emitted toward the + X-axis direction, and the emitted light emitted from the second LED 10B is emitted toward the + Y-axis direction. These emitted lights are collimated by the first and second collimator lenses 11A and 11B, intersected, and then condensed by the first and second condenser lenses 12A and 12B, respectively.

  The light emitted from the first LED 10A and collected by the first condenser lens 12A enters the first rod integrator 13A. The light that enters the first rod integrator 13A and travels in the + X-axis direction is reflected by the reflecting surface 13a and bent in the + Y-axis direction. Next, the light directed in the + Y-axis direction guided through the inside of the first rod integrator 13 </ b> A enters the rod integrator 15.

  On the other hand, the light emitted from the second LED 10B and collected by the second condenser lens 12B is incident on the second rod integrator 13B. The light that enters the second rod integrator 13B and travels in the + Y-axis direction is reflected by the reflecting surface 13b and bent in the + X-axis direction. Next, after guiding the inside of the second rod integrator 13 </ b> B, the light reflected by the reflecting surface 13 c is bent in the + Y axis direction and enters the rod integrator 15.

  According to the illuminating device 1 according to the present embodiment, the first and first optical paths are such that the optical path of the emitted light emitted from the first collimator lens 11A intersects the optical path of the emitted light emitted from the second collimator lens 11B. By disposing the second collimator lenses 11A and 11B and the first and second condenser lenses 12A and 12B, between the first and second collimator lenses 11A and 11B and the first and second rod integrators 13A and 13B. Space can be used effectively. Therefore, even when a plurality of LEDs 10A and 10B are used, the entire apparatus can be reduced in size, and bright and uniform illumination light can be obtained.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described with reference to FIG. In each embodiment described below, portions having the same configuration as those of the lighting device 1 according to the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.
The projector 30 according to this embodiment is different from the first embodiment in that three colors of red light, green light, and blue light are used as the illumination devices 40r, 40g, and 40b.

  As shown in FIG. 3, the projector 30 according to the present embodiment converts different color lights of R (red), G (green), and B (blue) emitted from the light source devices 41R, 51G, and 61B into the light modulation devices 70R, This is a three-plate type color projector that spatially modulates by 70G and 70B and combines by a dichroic prism 80 to display a color image.

FIG. 1 is a diagram showing an outline of a projector 30 according to this embodiment.
As shown in FIG. 1, the projector 30 includes an R light illumination device 40R that emits red laser light, a G light illumination device 40G that emits green laser light, and a B light that emits blue laser light. Lighting device 40B, and transmissive liquid crystal light valves (light modulation devices) 70R, 70G, and 70B that modulate the luminance of R, G, and B emitted from each of the lighting devices 40R, 40G, and 40B according to an image signal; A dichroic prism 80 that combines the modulated light beams to form a color image, and a projection lens (projection device) 90 that projects the color image emitted from the dichroic prism 80 onto the screen 100 are provided.

  The R light illumination device 40R includes a red LED (light source device) 41R that emits light in the + X-axis direction, a collimator lens (collimating optical system) 42 that collimates the emitted light emitted from the red LED 41R, and a collimator lens 42. A condensing lens (parallelizing optical system) 43 that condenses the light emitted from the light source, and a triangular prism 44 that bends the optical path of the light collected by the condensing lens 43 in the + X-axis direction by 90 degrees in the + Y-axis direction. A rod integrator (light guide element) 45 that equalizes the illuminance distribution of the light emitted from the triangular prism 44, a triangular prism 46 that bends the optical path of light toward the + Y axis direction by 90 degrees in the -X axis direction, and a triangle And a rod integrator 47 for making the illuminance distribution of the light emitted from the prism 46 uniform. The light emitted from the rod integrator 47 is directed to the transmissive liquid crystal light valve 70R.

  The G light illumination device 40G includes a green LED (light source device) 51G that emits light in the −X-axis direction, a collimator lens (parallelizing optical system) 52 that collimates the emitted light emitted from the green LED 51G, and a collimator lens. A condensing lens (collimating optical system) 53 that condenses the light emitted from 52, a triangular prism 54 that bends the optical path of light collected by the condensing lens 53 in the -X-axis direction by 90 degrees, A rod integrator (light guide element) 55 that equalizes the illuminance distribution of the light emitted from the triangular prism 54 is provided. The light emitted from the rod integrator 55 is directed to the transmissive liquid crystal light valve 70G.

  The illumination device for B light 40B includes a blue LED (light source device) 61B that emits light in the −X-axis direction, a collimator lens (parallelizing optical system) 62 that collimates the emitted light emitted from the blue LED 61B, and a collimator lens. A condensing lens (collimating optical system) 63 that condenses the light emitted from 62, and a triangle that bends the optical path of light collected by the condensing lens 63 toward the -X-axis direction by 90 degrees in the + Y-axis direction. The prism 64, the rod integrator 65 that equalizes the illuminance distribution of the light emitted from the triangular prism 64, the triangular prism 66 that bends the optical path of the light toward the + Y-axis direction by 90 degrees in the + X-axis direction, and the light emitted from the triangular prism 66. And a rod integrator 67 for making the illuminance distribution of the emitted light uniform. The light emitted from the rod integrator 67 is directed to the transmissive liquid crystal light valve 70B.

The rod integrator 45 and the rod integrator 55 are disposed between the collimator lens 62 and the condenser lens 63, and the red and green light paths that guide the inside of the rod integrator 45 and the rod integrator 55 and the collimator lens 62. Is arranged so as to intersect with the optical path of the blue light emitted from.
Further, the rod integrator 55 is disposed between the collimator lens 42 and the condenser lens 43. In other words, the rod integrator 55 is disposed so that the optical path of the green light guided inside intersects the optical path of the red light emitted from the collimator lens 42.

  Further, the optical system including the collimator lenses 42, 52, and 62 and the condensing lenses 43, 53, and 63 used in each of the lighting devices 40R, 40G, and 40B is a telecentric optical system as in the first embodiment. The emitted light emitted from the LEDs 41R, 51G, and 61B is imaged on the triangular prisms 44, 54, and 64, respectively.

Next, a method of projecting an image on the screen 100 using the projector 30 of the present embodiment having the above configuration will be described.
First, the effect | action about the red light inject | emitted from red LED41R is demonstrated. When a current is supplied to the R light LED 41R of the R light illumination device 40R, the R light is emitted from the R light LED 41R toward the collimator lens 42 as shown in FIG.

  Then, the light collimated by the collimator lens 42 passes through the rod integrator 55, is condensed by the condenser lens 43, and enters the triangular prism 44. The light reflected by the triangular prism 44 is guided through the rod integrator 45, reflected by the triangular prism 46, and enters the rod integrator 47. The light guided inside the rod integrator 47 enters the transmissive liquid crystal light valve 70R, and is then modulated based on the video signal input to the projector 30 and is emitted toward the dichroic prism 80.

  Next, the effect | action about the green light inject | emitted from green LED51G is demonstrated. When a current is supplied to the G light LED 51G of the G light illumination device 40G, the G light is emitted from the G light LED 51G toward the collimator lens 52 as shown in FIG.

  The light collimated by the collimator lens 52 is collected by the condenser lens 53 and enters the triangular prism 54. The light reflected by the triangular prism 54 is guided through the rod integrator 55, then reflected by the triangular prism 56, and enters the rod integrator 57. The light guided inside the rod integrator 57 enters the transmissive liquid crystal light valve 70G, and is then modulated based on the video signal input to the projector 30 and is emitted toward the dichroic prism 80.

  Next, the effect | action about the blue light inject | emitted from blue LED61B is demonstrated. When a current is supplied to the B light LED 61B of the B light illumination device 40B, B light is emitted from the B light LED 61B toward the collimator lens 62 as shown in FIG.

  Then, the light collimated by the collimator lens 62 passes through the rod integrator 45 and the rod integrator 55, is condensed by the condenser lens 63, and enters the triangular prism 64. The light reflected by the triangular prism 64 is guided through the rod integrator 65, reflected by the triangular prism 66, and enters the rod integrator 67. The light guided through the rod integrator 67 enters the transmissive liquid crystal light valve 70B, and is then modulated based on the video signal input to the projector 30 and is emitted toward the dichroic prism 80.

  R light, G light, and B light incident on the dichroic prism 80 are combined by a blue light reflecting dichroic film that reflects blue light and a green light reflecting dichroic film that reflects green light to form light representing a color image. Injected toward the projection lens 90. The projection lens 90 enlarges and projects light representing a color image toward the screen 100 to display a color image.

  According to the illumination devices 40 </ b> R, 40 </ b> G, and 40 </ b> B according to the present embodiment, the collimator lens 42 has an optical path of red light emitted from the collimator lens 42 intersecting an optical path of green light that guides the inside of the rod integrator 55. The collimator lens 62 is configured such that the optical path of the blue light emitted from the collimator lens 62 guides the inside of the rod integrator 45 and the optical path of the green light that guides the inside of the rod integrator 55. Therefore, the space between the collimator lens 42 and the condenser lens 43 and the space between the collimator lens 62 and the condenser lens 63 can be effectively utilized. Further, by arranging the rod integrators 45 and 55 in this space, it is possible to make the illuminance distribution of the green light and the red light uniform without providing a space occupied by the rod integrators 45 and 55 separately. Therefore, even when a plurality of LEDs 41R, LED51G, and LED61B are used, the entire apparatus can be downsized, and bright and uniform illumination light can be obtained. Furthermore, since the illumination devices 40R, 40G, and 40B irradiate uniform illumination light and are miniaturized, by using the illumination devices 40R, 40G, and 40B for the projector 30, an image with uniform brightness can be obtained. It becomes possible to project.

  In the present embodiment, the blue light emitted from the collimator lens 62 intersects the red light that guides the inside of the rod integrator 45 and the green light that guides the inside of the rod integrator 55, and further collimator lens 42. The red light emitted from the green light and the green light guided inside the rod integrator 55 are crossed. However, the crossed color light is not limited to this. For example, the red light emitted from the collimator lens 42 and the rod integrator Only the green light that guides the inside of 55 may be crossed. That is, at least one collimating optical system may be arranged so that the optical path between the plurality of lenses intersects with another optical path. Even with such a configuration, the effects of the present invention can be achieved. Furthermore, it is possible to appropriately change the color light and the components to be intersected.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, although the transmissive liquid crystal light valves 40R, 40G, and 40B are used as the light modulator, the present invention is not limited to this. For example, a reflective light modulator (mirror modulator) such as DMD (Digital Micromirror Device) is used. Also good.
In addition, although one collimating lens and one condensing lens are used as one collimating optical system, the number of collimating lenses is not limited to this, and the number of the collimating lenses can be changed according to the application.

It is a top view which shows the illuminating device which concerns on 1st Embodiment of this invention. It is the schematic which shows the telecentric optical system of FIG. It is a top view which shows the illuminating device which concerns on 2nd Embodiment of this invention.

Explanation of symbols

1, 40R, 40G, 40B ... illumination device, 10A ... first LED (light source device), 10B ... second LED (light source device), 11A ... collimator lens (parallelizing optical system), 11B ... collimator lens (parallelizing optical system) , 12A: first condensing lens (collimating optical system), 12B: second condensing lens (collimating optical system), 20: telecentric optical system, 30: projector, 41R: red LED (light source device), 42, 52, 62 ... collimator lens (collimating optical system), 43, 53, 63 ... condensing lens (parallelizing optical system), 51G ... green LED (light source device), 61B ... blue LED (light source device), 70R, 70G 70B: Transmission type liquid crystal light valve (light modulation device), 90: Projection lens (projection device)

Claims (4)

A plurality of light source devices for emitting light;
Parallelizing the emitted light emitted from the plurality of light source devices, respectively, and a plurality of collimating optical systems each including a plurality of lenses,
At least one of the plurality of collimating optical systems is arranged such that an optical path between the plurality of lenses intersects with another optical path.   The illumination device according to claim 1, wherein the collimating optical system is a telecentric optical system. A plurality of light guide elements for making uniform the illuminance distribution of the emitted light emitted from the plurality of collimating optical systems,
The at least one of the plurality of light guide elements is arranged so that an optical axis thereof intersects with an optical axis of emitted light emitted from the collimating optical system. 2. The illumination device according to 2. The lighting device according to any one of claims 1 to 3,
A light modulation device that modulates light emitted from the illumination device according to an image signal;
A projector comprising: a projection device that projects light modulated by the light modulation device.

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